US1335431A - Well-drilling taper tap - Google Patents

Description

-R. E. FAIR. WELL DRILLING TAPER TAP. APPLICATION FILED OCT. 4, I919.

1,335,431. Patented Mar. 30,1920,

* UNIT s'rarns earner RALPH EMERSON FAIR, 0F GHA'ITANQOGA, ASSIGNOR TO LUGEY MANU- FACTURING CORPORATION OF, TENIGESSEE, 0F OHATTANGOGA, TENNESSEE, A COR- POEATION OF TENNESSEE.

W'ELL-DRILLENG TAPER TAP.

To all whom it may concern:

Be it known that I, RALPH E. FAIR, a citizen oi the United States, residing at Chattanooga, in the county of Hamilton and State of Tennessee, have invented certain new and useful Improvements in lVell-Drilling Taper Taps; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable othersskilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which "form a part of this specification.

My invention relates to taper taps designed for use in the art of well-drilling for the purpose of engaging and removing from the well bore a piece of pipe which has become broken ofi' in the at of drilling the well and left at the bottom of the well. Heretot'ore a piece of broken pipe at the bottom of the well has been removed by means of a taper tap screwed into the end of the broken piece of pipe. My invention has for its object to improve taper taps of the type mentioned so that a body of water or water and mud may be pumped down through the taper tap and discharged therefrom at a point back from the end of the tap so as to wash away material which may have accumulated in and over the broken or lost piece of pipe so that the taper tap may then more readily find and enter the end of the broken piece of pipe, and also serve to give notice to the driller of the engagement of the tap with the broken pipe which notice will be given by reason of the increased pressure against which the pump will work occasioned by the tap filling the pipe which is to be removed.

To the accomplishment of the foregoing and such other objects as may hereinafter appear the invention consists in the features hereinafter particularly described and then sought to be clearly defined by the claims, reference being had to the accompanying drawing forming a part hereof, and in which 7 Figure l is a side view of the taper tap;

Fig. 2 an end View;

Fig. 3 a longitudinal section of a portion Specificaticn of Letters Patent iiatented Mar. 30, 1926.

Application filed October 4, 1919.

Serial No. 328,451.

of the tap, on an enlarged-scale, showing the threads on a 3 taper per ft;

Fig. 4 a longitudinal section on line of Fig. 2, with parts broken away.

In the drawing the tap is illustrated formed at one end with a threaded nipple or portion 1 to screw into a length or string of drill pipe by which the tap is lowered into the well, and at the other end is formed with a conical or'tapering point 2 which will enter the end of the broken or lost piece of pipe that is to be taken out of the well. The tap tapers longitudinally from end to end and is formed with longitudinally extending grooves or flutes 3, the body portions of the taper between the grooves being formed with screw threads The taper per foot and thenumber 01. threads per inch may vary to suit the conditions of the work for which the particular tap is designed. In the illustration given in the drawing the taper of the tap for a distance of approximately one inch back from the base of the conical point is three inches per foot, out after the threading has been filiGCJBCl, and from that point to the other end of the threaded portion the taper is approximately three quarters of an inch to the foot, and the threads are out eight to the inch. These proportions however, as stated, may be varied.

The tap is formed with a central bore 5 extending longitudinally from the nipple end that screws into the string of drill pipe to a point approximately ten inches, more or less, back from the base of the conical point of the tap, or the lower end of the threaded portion of the tap, and from the lower end portion of the bore, two or more holes or ports 6 are bored laterally and at an angle, from the outside of the tap to the interior of the bore, through the fluted portion of the tap. The purpose of the central bore and its lateral discharge ports is to receive water or fluid from the string of pipe to which the tap is attached and conduct it to a point where, when discharged through the lateral ports, .it will wash away material that may have collected in and over the broken section of pipe that is to be removed so that the conical end of the tap may more readily find and'enter the end of the broken pipe section so that the screw threads of the tap may, when the tap and string of pipe are rotated, come into threaded attachment to the broken pipe for the withdrawal of the section from the well.

Another purpose of the central bore and lateral discharge ports to the tap is to give notice to the driller when attachment has been made between the tap and broken section of pipe so that he may know when to proceed to withdraw the pipe from the well. This notice is given by the increased pressure against which the pump that forces the water, or mud and water, through the tap will work the tap enters the. broken piece of pipe. As the tap is lowered the water 7 escaping from the "lateral ports will find a return through the space between the tap and the wall of the pipe through which it is lowered, and as the tap enters the end of the broken piece of pipe the space for the flow of the water becomes somewhat restricted so that the pump works against a greater pressure. When the tap has entered the broken section sufficiently for its screw threads to make attaching engagement with the interior well of the broken section, and especially so when the ports of the tap have passed within the end of the broken section, the flow or discharge of the water is further restricted, and thedriller knows by the increased pressure against which the pump is working that attachment of the tap to the broken pipe has been effected and that he may proceed to withdraw the tap and at tached broken section of pipe from the well. It will thus-be observed that an important function is performed in this art by the construction of taper tap as described.

I have illustrated and described the preferred details of tap construction but it is to be understood that the shape and proportions may be changed without departing from the essential features oi the invention.

Having described my invention and set forth its merits what I claim is:

1. The well drilling tapertap comprising. the longitudii'ially tapering threaded body formed with a central longitudinal bore provided with lateral fluid discharge ports positioned adjacent the lower threaded portion of the body.

2. The well drilling taper tap comprising the longitudinally tapering threaded body portion formed with a central longitudinal bore provided with lateral fluid discharge ports disposed in an angular oblique relation to the bore and adjacent the lower threaded portion of the body.

The well drilling taper tap comprising the longitudinally tapering threaded body portion formed. with longitudinal flutes and a central longitudinally extending bore provided with lateral fluid discharge ports through the fluted portion and adjacent the lower threaded portion of the body;

a. The well drilling tap comprising the body portion threaded for attaching engagement with one end of a pipe to be lifted from a well and formed with a central longitudinally extending bore provided with a lateral fluid discharge port adjacent one end to clear material from the end of the section of pipe to be removed and indicate to the driller when attachment between the tap and pine section has been made.

In testimony whereof I afliX my signature in presence of two witnesses.

RALPH EMERSON FAIR.

Witnesses:

J. B. WVnLLs, H. L. THATCHER.

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